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Wednesday, April 23, 2008

Podcasting

Earlier this month I went to Portugal for the IADIS m-learning conference, a smallish conference on e-learning and mobile devices. The conference was really quite interesting, although it had a curiously ex-pat feel to it because of the number of UK delegates.

One presentation really got me thinking, it was an account from Malcolm Andrew, a lecturer in microbiology at De Montfort Univeristy, of how he has been using podcasts to support his teaching. I've been toying with the idea of podcasts for a while but couldn't quite decide how best to use them. If you do a whole-lecture will that mean that no-one turns up on the day? If you do supplementary material will anyone watch it? And if you make it part of a required reading exercise ("watch the podcast before the lecture folks") will they bother?

Malcolm has settled on an easy compromise, one of those things that's obvious once its been pointed out to you; he produces a 5-10 minute summary of each key idea in a course (normally one summary per lecture) using slides, simple animations and voiceovers. He doesn't ask the students to use the podcast in any particular way, and has observed that some watch it before a lecture, some afterward - some watch it on an iPod, some on the PC - some use it for revision, and a few don't watch it at all. Because a summary format is so flexible, students are able to bring the podcast into their own way of working, and because he keeps them short they are easy to watch, easier to make (they still take a bit of effort), and can be sampled as the students like, depending on their time and interest.

Do you ever get that feeling that you haven't seen the forest for the trees :-/

So, emboldened by Malcolm's example, when I returned to the UK I set about investigating how I could produce a few podcasts of my own. This involves two steps: producing the video and getting it hosted out there somehow.

After a few false starts the method I used to produce the video was:

Prepare slides in Powerpoint. Create a short PowerPoint presentation with an obvious structure, and simple individual slides. There are many ways to get PowerPoint into a video (not least of which is to select 'save as video' on the Mac version) however I found that the best way was actually to save the presentation as a set of images, and then import those images into a video editor. This means that you cant use animations (but most free video export methods don't support those anyway), but gives you a lot of control over timings and slide transitions.

Prepare a script. I tried a few times without one and it was a disaster. Ums and erms don't sound too bad (in moderation) when you're lecturing, but they sound dreadful on a video. A script makes you sound a bit mechanical, but at least it means that you end up saying what you meant to say, and when you're saving the whole thing for posterity that starts to matter!

Import the images into a video editor. I used iMovie, becuase it comes with the Mac and its easy to use. I guess that commercial stuff would be more powerful, but for my needs iMovie was just fine.

Record a section of the script for each slide and cut to size. iMovie has a voice over mode which allowed me to add a voice recording to each clip (every imported image appears as a clip). When importing I make each clip last 30 seconds, which is enough to make the recording, and then I reduce the length of the clip to match my voice over. Doing the voice over is actually quite tough; like most people I hate the sound of my own voice when played back to me (just who is that weird bloke talking - it sure as hell aint me?) and I tend to sound affected when I'm speaking very consciously, as a result I had to try hard to relax when I was recording (its still not perfect, but I got a lot better as I went on).

Add appropriate transitions. I used a fancy in-your-face cube rotation transition for each section (I want it to stand out), and more subtle fade-to-white transitions between slides. I also used cross-fades to allow multiple slides to gradually build up a diagram, which made up slightly for the lack of animation.

Save as a mp4 file (or other format, but mp4 is pretty flexible and allows you to store a master version at a decent resolution).

Once you have the video the next step is to get it online. The easy solution is to use YouTube or another video hosting site, but I'm a stubborn old GenXer with my own website, and so I need to convert and host it myself.

I used three pieces of software for this:

ffmpegX - this is a MacOS front end on the ffmpeg unix tools. It converts the mp4 file into a flv file (flash movie), which is the most popular way of putting video on the web at the moment (thanks in no small part to YouTube).

flv-duration - this is a small tool which adds duration meta-data to the FLV file, which allows FLV players to add a progress bar control that lets viewers move to whatever section of the video they like.

JW FLV Media Player - this is a flash video player that can load FLV files and play them within a webpage.

At the end of the whole shebang you end up with a hard-earned podcast you can embed like so:

To be honest I'm still astonished at how hard this is (even on the Mac) - perhaps its because I'm swimming against the flow, if I'd used YouTube to host it would have been a lot simpler, but a part of me doesn't want to hand over all my little video darlings to be skewered and critiqued by the slobbering hordes on YouTube :-/

We have a couple of projects within LSL that are looking at how you might host teaching resources in a friendly environment (the Faroes project), and how you might allow managed commenting and annotation of your hosted content (the Synote project). Eating some of our own dogfood has underlined for me how useful these two projects could be to teachers and lecturers.

Both of them hope to have beta versions available by the end of the year and now I have some podcasts of my own, I will be eager to try them out.